1. Field of the Invention
The present invention relates to motilin and more particularly to a cloned single-stranded DNA, (hereinafter simply refer to as single-strand DNA) comprising nucleotide sequence which encodes human motilin precursor, a cloned double-stranded DNA, (hereinafter simply refer to as double-strand DNA) consisting of the single-strand DNA and its complementary single-strand DNA, a fragment of the single- or double-strand DNA, and a plasmid, in which the double-strand DNA or its fragment is integrated, as well as a process for the preparation of the single- or double-strand DNA.
2. Related Arts
The motilin is one of peptide hormones, first isolated from mucous membrane of porcine upper small intestine and determined its amino acid sequence by Brown, J. C. et al ["Gastroenterology" Vol. 62, pages 401-404 (1972) and "Can. J. Biochem." Vol. 52, pages 7-8 (1974)].
The porcine motilin disclosed in such literatures is one extracted from the animal tissue, consists of 22 amino acids and has molecular weight of about 2700. It has been well known that the porcine motilin has a hypermotility action of digestive tract and contracting action of gastroduodenal and colonic smooth muscle therein, as physiological actions. As the hypermotility action, it has been reported that a staying period of time in stomach is shortened ["Gastroenterology" Vol. 80, pages 456-460 (1981)] and as the contracting action of smooth muscle in the digestive tract, it has been known that the motilin shows a strong contracting action to rabbit and human gastrantestinal tract, independent from a neuro system. Therefore, it has been considered that the motilin is useful for curing gastrointeropathies at the period of post-operation and for diagnosis thereof.
The motilin according to the prior arts has been obtained through extraction from porcine organ and thus it was quite difficult to obtain the same in a large amount. Further, a structure of human motilin has not yet been determined. Namely, the motilin has not actually been applied for clinical use, due to its poor productivity, in spite of that an effectiveness thereof as the agent for curing gastro-enteropathy has been expected.